Pilot-cell for electric storage batteries.



R. MAGRAB. PILOT CELL FOR ELECTRIC STORAGE BATTERIES.

APILIOATION FILED NOV. 19, 1909.

990,893., Patented May 2, 1911.

aonsarcxmacnaa, or CHICAGO, ILLINOIS.

PILOT-'CELL FOB ELECTRIC STORAGE BATTERIES.

Specification of Letters Patent.

Patented May 2, 1911.

Application filed November 19, 1909. Serial No. 528,871.

new and useful Improvements in Pilot-Cells for Electric Storage Batteries, of which the following is a full, clear, and precise speciication.

My invention relates to pilot cells for electric storage batteries and contem lates improved and more desirable and e cient construction and arrangement thereof.

In the use-ot` storage batteries particularly for electric vehicle work it is very desirable to be able to: ascertain `immediately at any time the state of the storage batteries particularly as to the available power at any time. As the charge or power in a battery at any time is directly proportional to the specific gravity of the electrolyte the state of the battery can be obtained from the reading of a hydrometer immersed in the electrolyte. It is very undesirable to carry delicate instruments such as hydrometers or thermometers about ones person or on a vehicle so that tests can be made at any' time, and furthermore, the batteries in a vehicle are usually; crowded' into'what space there is available and vare not readily accessible so that the instruments could not be readily i applied and tests made. The instruments, therefore, should be permanentlyassociated with the battery so that` readings can. bef taken without any prelim ary application or. adjustment of instrume ts. The'instru# ments, should, however, be so applied to the cell or cells that they will dccupy the least space and Wil be well protected.

Among the s lient objects of my invention,l therefore, are to provide an improved form of cell receptacle for accommodatin measuring instruments; to provide for suc accommodation of measuring instruments Without in any way interfering with the plates, electrolyte or other battery parts; to provide such accommodation without requiring additional vehicle space; to provide for ample protec-` tion off the instruments; to provide such con; struction and arrangement that the electrolyte will have -free access to the instruments; to provide means for illuminating the scale of the instruments; and in general to provide a pilot cell of more ecient and practiml arrangement and construction.

My invention is clearly described in the' the accompanying drawing, in which drawmg .Figure lis a plan view of one end of a cell showing the instrument compartment and the cap for said compartment partly broken away, Fig. 2 is a front elevation View of the parts shown in Fig. l, Fig. 3 is a sectional view taken on plane 3-3, Fi 2, Fig. 4 is a plan view partly in section o? the end of a cell receptacle showing a modified arrangement for providing the instrument compartment, and Fig. -5 is a plan view partly in section of one corner of a cell receptacle showing another modied arrangement for providing the instrument compartment.

The cell receptacle 1 which for vehicle use is usually of hard rubber is, in accordance with my invention, provided on one of its faces with a supplemental wall 2 which with the main Wall 3 of the receptacle forms a oompartmentor pocket 4 openI only at its upper end. This supplemen al wall may be of any shape, being shown as semi-circular in Figs. l, 2 and 3. The wall may primarily be separate and cemented or otherwise secured to the face of the receptacle or may be an integral part of the main receptacle 1, and the top of the wall is preferably flush with ythe top of the main receptacle, as shown. Along intermediate line 5 the wall 2 is ott'set to form an inner semi-annular shoulder 6 'for seating the lower edge of a semi-annular glass plate 7. Cut inthe front of Wall 2 above the offset line 5 is asight opening 8 which is closed by the glass plate. The ends 9-and 10 of the plate engage against the rea'r wall 3 and are slightly prolonged so that when the plate is applied its front surface will be pressed with sufficientforce against the rim 1-1 surrounding the sight opening 8 to seal the sight opening. The Wall 3 has a number of perforatlons l2 at various heights so that the electrolyte e may circulate freely through the supplemental compartment 4. The condition of the electrolyte can be readily adjudged by the gasi condition thereof, and for this purposet e uppermost of the perforations 12 preferably appears adjacent the surface of the electrolyte so that the operator when observing the indications on the instruments in the supplemental compartment can also through this up rmost perforation observe the gasing condltions. In the electrolyte 1n @his compartment is oated a hydrometer 13 whose I upper end extends past the sight opening 8 and is provided with suitable scale lmarks 14 indicative of the specific gravity of the electrolyte. If desired, a thermometer 15 ma also be immersed in the electrolyte with 1ts upper end extending across the sight opening 8 so that the temperature of the electrolyte can be observed.` The thermometer can readily be held in place against the wall 3 or wall 2. As shown, the thermometer 'is supported in its lower end in a cup frame 1G and its upper end is held in place by a strap 17, the cup frame and strap being preferably of leadin order to withstand the eli'ccts of the acid in the electrolyte. The specific gravity, the temperature and the gasing condition of the electrolyte can thus' be readily observed through the sight opening 8'- and the transparent glass plate 7 which seals the sight opening against the esca-pe of electrolyte. A cap 18 may be provided for'closing the upper end of the supplemental compartment and the up er end 7 of the glass plate 7 may extend a distance beyond the top-of the main and supplemental 4receptacles to forma. retaining extension for the ca It is ver desirab e that some illuminating .means e provided for enabling reading of the instruments in dark places,and a small electric lamp is preferably provided for throwing light rays against the scales of the instruments, As shown in Fig. 3 a desirable arrangement is to mount a lamp 19 on the inner side of the cover 18 and to roride light reflector 20 for reflecting the light rays against the upper end of the glass plate engaged by the rim ll'and cover 18. this section of the glass plate acting as a mirror to reflect the light rays toward the scaleson the instrument. A switch 21 is shown mounted on the cap for ,controlling the lampcurrent supply circuit 22 which may connect with the positive and negative plates 23 and 24 in the battery, the lampand its circuit controlling switch forming thus a fixed part of the cell. The lamp, could, however, be applied at some other part of the cell structure to direct its rays against the instrument scales, and the switching mechanism could also be in a different position from that shown.

In Figs. 4 and 5 are shown some modified arrangements for providing a supplemental measuring instrument compartment. In Fig. 4 a supplemental wall 25 extends across the corner of the receptacle and -forms with the outer Wall 3 of the receptacle the supplemental compartment 26. The sight opening 27 cut in the front wall 3 is sealed by a curved glss plate 28. In Fig.4 5 thesupplemental wall 29 is applied to the inner side of the main wall 3 of the receptacle and forme with the main wall the supplemental compartment 30 for receiving the measuring instruments. -The sight opening 31 cut in the' wall 3 is sealed by the cell is not increased materially so that the' cell will easily t in vehicles. The cells of a battery for vehicle use are lusually set in a crate which can easily be slightly remodeled without changing its general dimensions to accommodate the supplemental compartment of the pilot cell. The instruments are always in working condition and are amply protected, and readings can be taken therefrom without touching the cell, the illuminating lamp facilitating reading of the instruments in dark places. Ihe operator is, therefore, enabled to at any time ascertain the conditions of the storage batrIydo not wish to be limited to the precise constructions and arrangements herein shown, as changescould readily be made which would still come within the scope of `my invention, but I desireto secure the following claims by Letters-Patent. Y

1. In a pilot cellfor'storage batteries, the combination of a receptacle for accommodating electrodes and electrolyte, a vsupplemental wall coperatin with a section of the receptacle wall to orm a compartment for accommodating measuring instruments, said receptacle communicating with said compartment to allow access of the electrolyte to instruments placed5within the compartment, said compartment having 'an opening, a glass plate for sealing said opening an through which instruments can read, and a cover for said compartment, said glass plate extending ond the upper edge of the compartment wa ls to form a retaining ridge for said cover. c

2. A receptacle for containing a fluid, 'a supplemental arch-shaped wall section ap-l plied to one Wall of the receptacle, said supplemental wall section and the adjacent wall section of the receptacle serving to inclose 'supplemental wall section and the adjacent ment-al testing compartment, said adjacent opening thecondition o section having -small openings for allowing circulation between the receptacle and the testing compartment, said supplemental wall having a sight opening, and a semi-circular transparent plate wedged between said sup plemental wall and the adjacent section of the receptacle wall to securely seal the sight opening against escape of fluid, said test compartment Serving to accommodate instruments for indicatin through the sight the fluid.

4. A receptacle for storage batteries comprising a complete main`rece tacle part, and a supplemental wall section ridging a section of the main receptacle part wall and forming With said section a test pocket or compartment for accommodating instru ments for indicating the lcondition of electrolyte in the receptacle, said supplemental wall section having a sight opening adjacent the top of the electrolyte, there being openings through the section of the main 4receptacle bridgedby the supplemental wall section for allowing free circulation of electrolyte between the main receptacle part and the test pocket, one of said openings serving as a sight passageway into the main receptacle partadjacent the surface of the electrolyte whereby observation can be taken through the sight opening of the instruments in the test pocket and ofy the condition of the electrolyte at thesurface.

5. In an apparatus for indicating the condition of astorage battery, a receptacle communicating with the storage battery cell and formed in part by the Walls thereof, said receptacle being adapted to contain a portion of the electrolyte of said battery, a hydrom'eter in said receptacle, and a window of traisparent material secured to said receptac e. Y

In witness hereof, I hereunto subscribe my .name this 15th 'day of November, A. D. 1909.

RODERICK MACRAE.

Witnesses:

CHARIES J. SCHMIDT, NELLIE B. DEARBORN. 

